A nano-structured nickel trithiocarbonate complex supported on g-C3N4 as an efficient electrocatalyst for urea electro-oxidation

Abstract

Electrolysis of water is emerging as a potential technique for producing green hydrogen. However, the large overpotential due to the sluggish kinetics involved with the oxygen evolution reaction (OER) is coercing scientific communities toward finding alternative ways of hydrogen generation. Recently, the urea oxidation reaction (UOR) has evolved as a promising anode reaction for the electrocatalytic production of hydrogen. Herein, we report the fabrication of a composite of a nanostructured nickel(II) trithiocarbonate (Ni-ttc-d) complex with g-C₃N₄ fabricated by a simple mechanochemical method and demonstrate its use as a robust and efficient catalyst for the UOR. The 35-Ni-ttc-d/g-C₃N₄ composite with 35 weight% of Ni-ttc-d displayed the highest electrochemical surface area (ECSA) and double-layer capacitance (C_dl) along with the lowest R_ct and required a potential of 1.38 V (vs. RHE) to achieve a current density of 10 mA cm⁻² for the UOR, which is about 290 mV lower than that of the OER process. The Ni-ttc-d/C₃N₄ composite also showed excellent amperometric and potentiometric stability.